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Updated: May 26, 2026

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
Catalytic Generation of Cationic Gold Carbene Complexes From 7-Alkynylnorbornadienes and Their Intermolecular
Kento Ishida1, Kenta Toei1, Fumiaki Tomi1
1Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science (RIKADAI), Noda, Chiba, Japan.
Abstract:
Norbornene derivatives are commonly used in organic chemistry. The development of new norbornene derivatives is important for expanding molecular diversity. In this study, we investigated the cationic gold-catalyzed cycloisomerization of 7-alkynylnorbornadienes. The reaction of 7-alkynylnorbornadienes with an excess of alkenes in the presence of a catalytic amount of [IPrAu(MeCN)]SbF6 efficiently afforded a new class of norbornene derivatives through intermolecular cyclopropanation of cyclopropyl gold carbene complexes. This reaction exhibited a wide substrate scope, and the product was demonstrated to be applicable to polymer synthesis and click reactions. Furthermore, DFT studies suggested that the developed reaction proceeds via a mechanism involving a gold(III) metallacyclobutane intermediate, which is different from the mechanisms previously reported for cationic gold(I)-catalyzed styrene cyclopropanation.
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